The present invention relates generally to passenger loading bridges and more particularly to automated passenger loading bridges for servicing an aircraft absent the intervention of a bridge-operator.
In order to make aircraft passengers comfortable, and in order to transport them between the airport terminal and the aircraft in such a way that they are protected from weather and other environmental influences, passenger loading bridges are used which can be telescopically extended and the height of which is adjustable. For instance, an apron drive bridge in present day use comprises a plurality of adjustable modules, including: a rotunda, a telescopic tunnel, a bubble section, a cab, and elevating columns with wheel carriage. Manual, semi-automated and fully-automated bridge alignment systems are known in the prior art for adjusting the position of the passenger loading bridge relative to an aircraft, for instance to compensate for different sized aircraft and to compensate for imprecise parking of an aircraft at an airport terminal, etc. Of course, other types of bridges are known in the art, such as for example nose loaders and pedestal bridges.
Often, manual bridge alignment systems are preferred by the airlines because a trained bridge-operator is present and is able to observe directly the movements of the bridge relative to the aircraft. Typically, the bridge-operator uses a control panel located within the cab section to adjust the bridge each time a flight arrives. Accordingly, the probability that the bridge will collide with an aircraft during an alignment operation is relatively small. It is in the airlines"" best interest that such collisions are avoided, as the bridge is massive and may be moving rapidly, and accordingly even a relatively minor collision involving an aircraft and a passenger loading bridge can cause extensive damage to the aircraft. Of course, there is also a danger that such a collision will result in a fuel leak, thereby increasing the possibility of a fire or explosion near the terminal building. Furthermore, as an airline is unlikely to have an extra aircraft waiting and ready to fly, passengers are inconvenienced unnecessarily by having their flight cancelled.
Of secondary concern to the airlines is ensuring that the passenger bridge is aligned with the aircraft as rapidly as possible, thereby minimizing the time to complete passenger deplaning, cleaning, restocking etc. As such, semi-automated bridge alignment systems are known in the prior art, which systems allow the bridge to be moved rapidly to a preset position under the control of a computer. For example, some passenger bridges are equipped with controls which automatically cause the height adjustment mechanism to move the cab to a predetermined height. One type of automatic control for a vertical height adjustment mechanism includes an electric control which has a console equipped with a number of push button type switches, each of which is labeled with the name of a different type of aircraft. Actuating a switch causes the mechanism to move the bridge column to a preset location so that the cab is properly aligned with the door of the type of aircraft named on the switch label. Each switch in the console is connected to a mechanically actuated switch located adjacent the bridge column. When a switch is actuated, the bridge is moved until a cam mounted on the bridge column trips the mechanical switch, which interrupts power to the motor. The cam is positioned to trip the switch when the bridge reaches the preset position. Unfortunately, the bridge-operator must be present to press the switch for enabling the automated height adjustment. As such, the bridge-operator must arrive at the passenger bridge in advance of the aircraft, which wastes the time of the operator, or alternatively the bridge-operator initiates the height adjustment after the aircraft has arrived at the bridge, which inconveniences the passengers aboard the aircraft.
Schoenberger et al. in U.S. Pat. No. 5,226,204 describes an automatic loading bridge that uses video cameras in the control of the bridge. The system maneuvers an end of the bridge to a position close to the door, whereupon an operator controls the bridge during the last part of its movement by looking at images recorded by the video cameras. Suggestions are made in the patent specification that the system could be arranged to operate fully automatically using image-processing of the recorded images to calculate the distance between the bridge and the aircraft. However, image-processing is time-consuming, thus making the movement based thereon slow.
WO 96/08411, filed Sep. 14, 1995 in the name of Anderberg, describes a device for controlling the movement of a passenger bridge. When an aircraft has landed, a central computer, such as for instance a central computer located within a terminal building, transmits information on the type of aircraft to a local computer of the passenger bridge at an assigned gate. The local computer accesses a database and retrieves information on the positions of the doors for the type of aircraft that has landed, as well as information on the expected stop position for the type of aircraft at the assigned gate. The retrieved information allows the local computer to determine an absolute position of the door with which the bridge is to be aligned. Accordingly, the passenger bridge is moved under computer control to a position close to the determined position of the door, for example within 2-10 meters. The system includes sensors for providing real-time positional data for a cab end of the bridge to the local computer. The system further includes an electromagnetic distance meter for detecting the close approach of the passenger bridge to the aircraft and for reducing the speed of the passenger bridge in dependence thereon. Optionally, the bridge is preset to this position before the aircraft has stopped moving.
WO 01/34467, filed Nov. 8, 2000 also in the name of Anderberg, teaches that the above system is reliable only for movement to a position close to the aircraft. Thus, the bridge has to be operated manually during the remaining 2-10 meters of its movement. The WO 01/34467 reference also teaches an improvement to the above system, in which electromagnetic sensors are disposed along the distal end of the passenger loading bridge for transmitting a set of electromagnetic pulses in different directions and for detecting electromagnetic pulses after reflection on a craft. Based on the elapsed time between transmitting and detecting the electromagnetic pulses in different directions, a profile of distance as a function of direction is obtained. From the measured distance versus direction profile and the information stored in the computer, it is then possible to maneuver the bridge to the door of the craft.
Often, the tendency of an airline and/or an airport authority is to resist the implementation of a fully-automated passenger bridge alignment system because such systems lack a human operator""s ability to anticipate a future problem with an alignment operation and to take preemptive action in order to avoid a collision. Furthermore, a first airline may be willing to tolerate a relatively higher probability of collision than a second airline, in order to utilize fully-automated bridge alignment more often, and thereby minimize turnaround time for their airplanes. As such, a fully-automated passenger bridge alignment system preferably includes a safety system for assessing a level of risk associated with a next bridge movement, and for comparing the level of risk to a predetermined threshold value. Most preferably, the predetermined threshold value is set to one of a default value, an airline specified threshold value and a threshold value that is imposed by local government and/or airport authorities.
It is a disadvantage of the system disclosed by Anderberg in WO 01/34467 that a movement of the passenger bridge is controlled in dependence upon sensed data, which is collected approximately coincidentally with the movement of the passenger bridge. Anderberg does not teach using the sensed data and previously sensed data to determine a risk associated with a future movement of the bridge, and as such the system cannot anticipate a problem associated with a next step of the passenger bridge movement. Furthermore, the system does not allow for individual airlines and/or authorities to specify an acceptable level of risk associated with moving the passenger bridge under computer control toward an aircraft.
It is a further disadvantage of both of the systems that are disclosed by Anderberg that information on the type of aircraft is obtained from an external information source, such as for instance a central computer located within a terminal building. Every maneuver of the bridge is performed in dependence upon knowing specific parameters for the instantaneous aircraft model, such as for instance the position of the door and the expected stopping position. Although the specific parameters are stored locally for every model of aircraft, only the central computer can provide information on the model of aircraft that has landed. It is a further disadvantage that the central computer may serve a plurality of bridges at an airport. As such, if there is a problem with the central computer then every one of the passenger bridges in communication therewith will go offline, and automated alignment will not be possible. Of course, at a highly automated airport, there is unlikely to be a sufficient number of bridge-operators to manually align every bridge until the system is repaired. It will therefore be necessary to xe2x80x98mirrorxe2x80x99 the central computer using a redundant computer system, which unnecessarily adds expense. Alternatively, as suggested by Anderberg, the information on aircraft model is provided via a local data input device every time a flight arrives. Of course, a system in which a human must provide the aircraft model carries a greatly increased risk that an incorrect aircraft model will be provided as a result of human error particularly when similar designations such as xe2x80x9c727xe2x80x9d, xe2x80x9c737xe2x80x9d, xe2x80x9c747xe2x80x9d, xe2x80x9c757xe2x80x9d have been used to identify aircraft models.
Another disadvantage of the system disclosed by Anderberg is that the central computer requires access to a flight information database of the airport. Such a database must be set up to be accessible by the central computer, and there may be serious security-related issues involved with providing widely distributed access to flight information. Furthermore, many airports around the world do not support databases that would be suitable for interfacing with a passenger bridge system as described by Anderberg. In those cases, the authorities considering an automated passenger bridge would demand a system capable of completely autonomous operation.
Yet another disadvantage of the system disclosed by Anderberg is that the system does not verify the type of aircraft until after the aircraft has come to a halt. This is undesirable for two reasons. First, if due to human error or some other reason the type of aircraft that is transmitted to the bridge is incorrect, then the bridge may be preset to a position in which a collision with the aircraft will occur. Secondly, if the type of aircraft is incorrect and a collision does not occur, then additional bridge positioning must be performed after the aircraft has stopped and has been correctly identified. Any additional positioning of the bridge after the aircraft has stopped will inconvenience the passengers aboard the aircraft.
It would be advantageous to provide a passenger bridge control system that pre-identifies the model of an aircraft that has landed without requiring access to an external flight-schedule database. It would be further advantageous to provide a passenger bridge control system for performing a passenger bridge alignment operation absent bridge-operator intervention, wherein the operation is monitored to ensure that future alignment steps are safe within a selectable predetermined tolerance. Such a control system is more flexible, and allows an airline to define an acceptable level of risk and thereby balance the advantage of rapid, automated bridge alignment against the disadvantage of a collision occurring. Alternatively, government authorities or an airport authority will determine this balance.
In an attempt to overcome these and other limitations of the prior art it is an object of the instant invention to provide an apparatus and method for aligning automatically with the door of an aircraft, absent a collision occurring therebetween.
In an attempt to overcome these and other limitations of the prior art it is another object of the instant invention to provide an apparatus and method that allows a user to specify conditions under which an alignment operation may occur in an automated manner.
In accordance with an aspect of the instant invention there is provided an apparatus for positioning one end of a moveable bridge in relation to a door on a craft comprising:
a sensor for transmitting light and for detecting said light, to determine the position of the one end of the moveable bridge in relation to the craft and for providing a signal in dependence thereon; and,
a processor for receiving the signal from the sensor and for determining a next movement of the one end of the moveable bridge in dependence upon the signal, the processor also for determining an error factor in the determination of the next movement of the one end of the moveable bridge and for performing one of i) stopping the movement of the one end of the moveable bridge prior to performing the determined next movement and in dependence upon the determined error factor being within a first predetermined range of values, and ii) automatically performing the determined next movement of the one end of the moveable bridge in dependence upon the determined error factor being within a second other predetermined range of values not overlapping the first predetermined range of values.
In accordance with another aspect of the instant invention there is provided an apparatus for prepositioning a passenger bridge in relation to a door on an aircraft comprising:
a passenger bridge including a first end moveable for abutting an aircraft having a door and a second end for fixedly engaging a building;
a sensor for transmitting light and for detecting said light, to determine the position of the first end of the passenger bridge in relation to the aircraft and for providing a signal in dependence thereof;
a processor for receiving the signal from the sensor and for determining a next movement of the first end of the passenger bridge in dependence upon the signal, the processor also for determining an error factor in the determination of the next movement of the bridge and for comparing the determined error factor to a threshold value and for providing a control signal in dependence upon the determined error factor;
a memory in communication with the processor for storing template data relating to an extractable feature for a plurality of different models of aircrafts relative to which the first end of the passenger bridge is to be positioned; and,
a mechanism in communication with the processor for receiving the control signal therefrom, the mechanism for prepositioning the first end of the passenger bridge to a predetermined position in dependence upon the received control signal.
In accordance with another aspect of the instant invention there is further provided an apparatus for positioning one end of a moveable bridge in relation to a door on a craft comprising:
an imager for capturing a plurality of images of a craft and for providing a signal indicative of some of the plurality of images;
an image processor for receiving the signal from the imager, for determining a craft model therefrom, and for providing a second signal indicative of the determined craft model; and,
a controller for receiving the second signal from the image processor and for determining a next movement of the one end of the moveable bridge in dependence upon the second signal, the processor also for determining an error factor in the determination of the next movement of the one end of the moveable bridge and for i) stopping the movement of the one end of the moveable bridge in dependence upon the determined error factor being within a first predetermined range of values, and ii) automatically performing the determined next movement of the one end of the moveable bridge in dependence upon the determined error factor being within a second other predetermined range of values not overlapping the first predetermined range of values.
In accordance with another aspect of the instant invention there is further provided a method for positioning one end of a moveable bridge in relation to a door on a craft comprising the steps of:
a) determining the position of the one end of the moveable bridge in relation to the craft;
b) determining a next movement of the one end of the moveable bridge in dependence upon the determined position, the next movement of the one end of the moveable bridge for moving the one end of the moveable bridge toward the craft;
c) determining an error factor associated with the determination of the next movement of the one end of the moveable bridge; and,
d) performing the determined next movement of the bridge in dependence upon the determined error factor being within a predetermined range of values.
In accordance with another aspect of the instant invention there is further provided a method for positioning one end of a moveable bridge in relation to a door on an aircraft comprising the steps of:
a) determining the position of the one end of the moveable bridge in relation to the aircraft;
b) identifying a model of the aircraft and retrieving information relating to the position of a door on the identified model of the aircraft;
c) determining, in dependence upon the retrieved information, an expected stopping position of the door on the identified model of the aircraft;
d) determining a next movement of the one end of the moveable bridge in dependence upon the determined position of the one end of the moveable bridge and the expected stopping position of the door on the identified model of the aircraft, the next movement of the one end of the moveable bridge for moving the one end of the moveable bridge toward the expected stopping position of the door on the identified model of the aircraft;
e) determining an error factor associated with the determination of the next movement of the one end of the moveable bridge; and,
f) performing the determined next movement of the bridge in dependence upon the determined error factor being within a predetermined range of values.
In accordance with another aspect of the instant invention there is further provided an apparatus for positioning one end of a moveable bridge in relation to a door on a craft comprising:
a sensor for sensing a location of the craft relative to the one end of the moveable bridge and for providing sensor data in dependence upon the sensed location; and, a controller for receiving the sensor data, and for determining a next movement of the one end of the moveable bridge toward the sensed craft in dependence upon the sensor data, the controller also for determining an error factor in the determination of the next movement of the one end of the moveable bridge toward the sensed craft and for performing one of i) stopping the movement of the one end of the moveable bridge prior to performing the determined next movement and in dependence upon the determined error factor being within a first predetermined range of values, and ii) automatically performing the determined next movement of the one end of the moveable bridge toward the sensed craft in dependence upon the determined error factor being within a second other predetermined range of values not overlapping the first predetermined range of values.